1. Field of Invention
This invention is related to a process for the production of alkylene carbonates and oxides, and particularly to the production of propylene carbonate through a process comprising reacting propylene with a thallic salt of a carboxylic acid or thallic oxide and a carboxylic acid and carbon dioxide in an aqueous, organic solvent medium.
The olefin, e.g. (alkylene) carbonate products obtained through the process of this invention are useful commercial articles, particularly as reactants for the preparation of alkylene oxides such as propylene oxide through the decomposition of the carbonate and as organic polymer fiber forming resin solvents.
2. Description of Prior Art
W. Kruse, et al, J. Org. Chem. 30th Vol. pp.114 (71), describes the preparation of certain selected epoxides through the oxidation of the corresponding olefin with thallic acetate in weakly solvating media. No carbon dioxide is present in the Kruse system.
The Prior Art discloses several methods for the production and use of aklylene carbonates, and particularly ethylene and propylene carbonates. Alkylene carbonates have been made by at least three different approaches to date. One such technique is by the reaction of the corresponding alkylene oxide with carbon dioxide. Examples of this reaction can be seen in U.S. Pat. Nos. 2,667,497, 2,773,881 and 4,233,221. Naito et al., Chem. Soc. of Japan (82) No. 2 pp.290 discloses the free anionic additions of oxirane and its alkyl, aryl and halomethyl derivatives with carbon dioxide catalyzed by potassium carboxylates or carbonates through the addition of the crown ether, resulting in the formation of five membered cyclic carbonates.
Another technique is through the reaction of carbon dioxide with selected halohydrins. In U.S. Pat. No. 1,907,891 alkali carbonates are reacted with vicinal glycol chlorohydrins to produce the corresponding alkylene carbonates. In U.S. Pat. No. 2,784,201, the chlorohydrin is reacted with an alkali metal lower alkyl carbonate. In U.S. Pat. No. 3,923,842, as part of a three-step process to produce an alkylene oxide, the second step involves the reaction of a halohydrin with carbon dioxide to form an alkylene carbonate. Similar reactions are also revealed in U.S. Pat. Nos. 4,226,778 and 4,231,937.
Still another approach involves the direct reaction of olefins with carbon dioxide to produce alkylene carbonates. In U.S. Pat. No. 3,205,305 this reaction is carried out in the presence of two catalysts; the first a heavy metal oxide compound and the second a halide or hydroxy form of an ammonium compound. In U.S. Pat. No. 4,009,183 the reaction is carried out in the presence of an elemental iodine or iodide compound and a manganese compound. In U.S. Pat. No. 4,325,874 a process for the preparation of alkylene carbonates through the reaction of the corresponding olefins with carbon dioxide in the presence of iodine or an iodide compound and an oxide or a weak acid salt of thallium(III) is disclosed. U.S. Pat. No. 4,247,465 discloses the preparation of a cyclic alkylene carbonate ester from the reaction of an olefin with carbon dioxide and oxygen in the presence of an iodine-iron catalyst.
Oxidation of thallous compounds to their thallic forms have been disclosed in various publications. A number of these are discussed in U.S. Pat. No. 4,192,814.
All of these reactions, however, have the drawback of involving at least one of the following impediments; very high working temperatures and pressures, the use of toxic reagents such as phosgene, which give rise to the collateral formation of undesired by-products such as glycols which are difficult to separate, or, the use of corrosive reagents such as iodine which can gradually destroy reaction equipment and other containers. In particular, no reaction to date has been able to directly prepare alkylene carbonates from the corresponding olefins without the use of corrosive halides or some other serious process flaw.